1. Field of the Invention
The present invention relates in general to servo control systems, and more particularly, to a scaleable motion controller that can control multiple servo motors in a motion control system.
2. Background of the Invention
Motion control systems are used in applications such as robotics and material handling. A single axis motion control system typically comprises a motor, an encoder, an amplifier, and a motion controller. In general, motion is controlled by providing signals representing the position of the motor shaft to the motion controller via the encoder. Based on the actual position of the motor shaft and the desired position of the motor shaft, the motion controller outputs signals to the motor via the amplifier driving the motor to the desired position.
An n-axis motion control system comprises n motors with corresponding encoders and amplifiers. A single motion controller may be used for motion control in an n-axis motion control system if the motion controller has at least n processors, one for each motor. In general, motion is controlled in an n-axis motion control system by providing signals representing the positions of the motor shafts of each of the n motors to the motion controller via the respective n encoders. Based on the actual positions of the motor shafts of the n motors and the desired position of the motor shafts of the n motors, the motion controller outputs signals to the n motors via the n amplifiers, respectively. If the number of processors needed exceeds the number of processors that can fit on a single motion controller, then additional motion controllers will be needed.
Traditional motion controllers comprise a fixed number of processors. That is, these motion controllers are not designed to allow a user to purchase only the number of processors needed for a particular project. For example, for a 2-axis motion control system where only two processors are needed, a user must purchase a motion controller having four processors fixed to the motion controller even though the user needs only two of the processors does not need the remaining two processors fixed to the motion controller. Because motion controller must be purchased with a predetermined number of processor fixed to the motion controller, a user must pay for more processors than need. This makes motion controller very costly.
Accordingly, there is a need for a scalable motion controller where a user may select the number of processors needed for a particular application and use only the number of processors required on the motion controller.
In accordance with the invention, there is provided a scalable motion controller for controlling a plurality of servo motors in a motion control system. The scalable motion controller comprises means for inserting and removing one or more motion control processors and means for stacking a plurality of scalable motion controllers.
Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.